SQLite3 migrations can fail when used quoted db_table.

[Maciej Olko]

If model's Meta db_table is quoted, e.g. '"table_with_quoted_name"', SQLite3 migration with this table creation with can fail with django.db.utils.OperationalError: near "table_with_quoted_name": syntax error.

I suppose following generated query causes the error:

CREATE TABLE "new__"table_with_quoted_name"" ("obj_id" integer NOT NULL PRIMARY KEY, "obj_num" varchar(20) NULL,  "country_id" integer NOT NULL REFERENCES "countries" ("country_id") DEFERRABLE INITIALLY DEFERRED)

To reproduce table with quoted name should have at least one foreign key.

Django documentation says it supports quoted names (​https://docs.djangoproject.com/en/2.2/ref/databases/#naming-issues).

Quoted names can also be used with Django’s other supported database backends; except for Oracle, however, the quotes have no effect.

Traceback:

Traceback (most recent call last):
  File "…/django/db/backends/utils.py", line 82, in _execute
    return self.cursor.execute(sql)
  File "…/django/db/backends/sqlite3/base.py", line 382, in execute
    return Database.Cursor.execute(self, query)
sqlite3.OperationalError: near "table_with_quoted_name": syntax error

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "./manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  …
  File "…/django/core/management/commands/migrate.py", line 234, in handle
    fake_initial=fake_initial,
  File "…/django/db/migrations/executor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "…/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "…/django/db/migrations/executor.py", line 245, in apply_migration
    state = migration.apply(state, schema_editor)
  File "…/django/db/migrations/migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "…/django/db/migrations/operations/fields.py", line 112, in database_forwards
    field,
  File "…/django/db/backends/sqlite3/schema.py", line 327, in add_field
    self._remake_table(model, create_field=field)
  File "…/django/db/backends/sqlite3/schema.py", line 279, in _remake_table
    self.create_model(new_model)
  File "…/django/db/backends/base/schema.py", line 307, in create_model
    self.execute(sql, params or None)
  File "…/django/db/backends/base/schema.py", line 137, in execute
    cursor.execute(sql, params)
  File "…/django/db/backends/utils.py", line 99, in execute
    return super().execute(sql, params)
  File "…/django/db/backends/utils.py", line 67, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "…/django/db/backends/utils.py", line 76, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "…/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "…/django/db/utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "…/django/db/backends/utils.py", line 82, in _execute
    return self.cursor.execute(sql)
  File "…/django/db/backends/sqlite3/base.py", line 382, in execute
    return Database.Cursor.execute(self, query)
django.db.utils.OperationalError: near "table_with_quoted_name": syntax error

[Mariusz Felisiak]

Thanks for the report. I was able to reproduce this issue with AddField() when adding a new ForeignKey but probably few more operations are affected because ​_remake_table() is used widely in the SQLite backend. This should be easy to fix by unquoting ​db_table.

Reproduced at 4122d9d3f1983eea612f236e941d937bd8589a0d.

[Ngalim Siregar]

Created ​PR, but I am not sure why docs and isort failing.

[Simon Charette]

Patch is targeting model names containing quotes while the changes should live in _remake_table as pointed out by Mariusz.

@Ngalim you'll want to change ​this line to perform .strip('"') to strip possibly leading and trailing ".

[Ngalim Siregar]

Sorry, I was misunderstood the intent. I have made the requested changes; please review again

[Mariusz Felisiak <felisiak.mariusz@…>]

In e4684220:

Fixed #30664 -- Fixed migrations crash when altering table on SQLite or altering AutoField/BigAutoField on PostgreSQL for models with quoted db_table.

[Mariusz Felisiak <felisiak.mariusz@…>]

In ff111ea:

Refs #30664 -- Fixed migrations crash when altering AutoField/BigAutoField with quoted db_column on PostgreSQL.